Processing biomass

ABSTRACT

Carbon-containing materials, such as biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) or coal are processed to produce useful products, such as fuels, carboxylic acids and equivalents thereof (e.g., esters and salts). For example, systems are described that can use feedstock materials, such as cellulosic and/or lignocellulosic materials and/or starchy materials, to produce ethanol, butanol or organic acids (e.g., acetic or lactic acid), salts of organic acids or mixtures thereof. If desired, organic acids can be converted into alcohols, such as by first converting the acid, salt or mixtures of the acid and its salt to an ester, and then hydrogenating the formed ester. Acetogens or homoacetogens which are capable of utilizing a syngas from a thermochemical conversion of coal or biomass can be utilized to produce the desired product.

RELATED APPLICATIONS

This application is a continuation of PCT/US2010/020449, filed Jan. 8,2010, which claimed priority from U.S. Provisional Application Ser. No.61/147,377, filed on Jan. 26, 2009. The entirety of each of theseapplications is incorporated herein by reference.

TECHNICAL FIELD

This invention relates to processing biomass and products madetherefrom.

BACKGROUND

Various carbohydrates, such as cellulosic and lignocellulosic materials,e.g., in fibrous form, are produced, processed, and used in largequantities in a number of applications. Often such materials are usedonce, and then discarded as waste, or are simply considered to be wastematerials, e.g., sewage, bagasse, sawdust, and stover.

Various cellulosic and lignocellulosic materials, their uses, andapplications have been described in U.S. Pat. Nos. 7,307,108, 7,074,918,6,448,307, 6,258,876, 6,207,729, 5,973,035 and 5,952,105; and in variouspatent applications, including “FIBROUS MATERIALS AND COMPOSITES,”PCT/US2006/010648, filed on Mar. 23, 2006, AND “FIBROUS MATERIALS ANDCOMPOSITES,” U.S. Patent Application Publication No. 2007/0045456.

SUMMARY

Generally, this invention relates to carbon-containing materials, suchas carbohydrate-containing materials (e.g., starchy materials and/orcellulosic or lignocellulosic materials), methods of making andprocessing such materials to change their structure and/or theirrecalcitrance level, and products made from the changed materials. Forexample, many of the methods described herein can provide cellulosicand/or lignocellulosic materials that have a lower recalcitrance level,a lower molecular weight, a different level of functionalization and/orcrystallinity relative to a native material. Many of the methods providematerials that can be more readily utilized by a variety ofmicroorganisms, such as one or more homoacetogens or heteroacetogens(with or without enzymatic hydrolysis assistance) to produce usefulproducts, such as hydrogen, alcohols (e.g., ethanol or butanol), organicacids (e.g., acetic acid and/or lactic acid), hydrocarbons, co-products(e.g., proteins, such as single cell proteins) or mixtures of any ofthese.

Many of the products obtained, such as ethanol or n-butanol, can beutilized directly as a fuel or as a blend with other components, such asgasoline, for powering cars, trucks, tractors, ships or trains, e.g., asan internal combustion fuel or as a fuel cell feedstock. Other productsdescribed herein (e.g., organic acids, such as acetic acid and/or lacticacid) can be converted to other moieties (e.g., esters or anhydrides)that can be converted and utilized as a fuel. Many of the productsobtained can also be utilized to power aircraft, such as planes, e.g.,having jet engines, or helicopters. In addition, the products describedherein can be utilized for electrical power generation, e.g., in aconventional steam generating plant or in a fuel cell plant.

Exemplary products that can be produced by employing the methodsdescribed herein include hydrocarbons, proteins, alcohols (e.g., amonohydric alcohols or a dihydric alcohols), such as ethanol, n-propanolor n-butanol, carboxylic acids, such as acetic acid or butyric acid,salts of a carboxylic acid, a mixture of carboxylic acids and salts ofcarboxylic acids and esters of carboxylic acids (e.g., methyl, ethyl andn-propyl esters), ketones, aldehydes, alpha, beta unsaturated acids,such as acrylic acid and olefins, such as ethylene. Specific examplesinclude ethanol, propanol, propylene glycol, butanol, 1,4-butanediol,1,3-propanediol, methyl or ethyl esters of any of these alcohols, methylacrylate, methylmethacrylate, lactic acid, propionic acid, butyric acid,succinic acid, 3-hydroxypropionic acid, a salt of any of the acids and amixture of any of the acids and respective salts.

In one aspect, the invention features methods of making an alcohol, acarboxylic acid, a salt of a carboxylic acid, an ester of a carboxylicacid, or a mixture of any of these. The methods include treating acarbon-containing material, such a biomass material or coal, with anytreatment method described herein, such as with one or more ofradiation, sonication, pyrolysis, oxidation and steam explosion; andconverting at least a portion of the treated carbon-containing materialutilizing a microorganism to produce a product that includes one or moreof an alcohol, a carboxylic acid, a salt of a carboxylic acid, acarboxylic acid ester or a mixture of any of these. The methods canfurther include acidifying, esterifying and/or hydrogenating theproduct. For example, acetogens or homoacetogens, which are capable ofutilizing a syngas from a thermochemical conversion process, can beutilized to enhance the efficiency of the conversion.

In another aspect, the invention features methods of making one or morealcohols that include treating a carbon-containing material, such as abiomass material and/or coal, with one or more of radiation, sonication,pyrolysis, oxidation and steam explosion; converting at least a portionof the treated carbon-containing material utilizing a microorganism,such as one or more acetogens or homoacetogens which are capable ofutilizing a syngas from the thermochemical conversion of coal orbiomass, to a product that includes a carboxylic acid, a salt of acarboxylic acid, a carboxylic acid ester or a mixture of any of these;and hydrogenating the product to produce alcohol.

Carbon dioxide generated and/or lignin liberated in any processdescribed herein can be captured. Any captured carbon dioxide can besequestered, e.g., by injecting the captured carbon dioxide into ageological formation capable of maintaining the carbon dioxide, e.g.,for a period of time greater than 100 years, e.g., greater than 250years, 500 years, 1,000 years or greater than 10,000 years. For example,any carbon dioxide produced in any process described herein can besequestered, e.g., by fixing carbon dioxide utilizing any microorganismdescribed herein. For example, the microorganism can include algae andthe carbon dioxide can be sequestered in the form of a carbohydrateand/or lipid. If desired, e.g., to produce a bio-diesel, the lipid canbe converted into an ester, e.g., a methyl, ethyl or propyl ester.

Changing a molecular structure of a material, as used herein, means tochange the chemical bonding arrangement or conformation of thestructure. For example, the change in the molecular structure caninclude changing the supramolecular structure of the material, oxidationof the material, changing an average molecular weight, changing anaverage crystallinity, changing a surface area, changing a degree ofpolymerization, changing a porosity, changing a degree of branching,grafting on other materials, changing a crystalline domain size, orchanging an overall domain size.

All publications, patent applications, patents, and other referencesmentioned herein or attached hereto are incorporated by reference intheir entirety for all that they contain.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a process for reducingrecalcitrance of a recalcitrant material.

FIG. 1A is a schematic diagram illustrating conversion of sugars derivedfrom biomass into ethanol.

FIG. 1B is a schematic diagram illustrating conversion of sugars derivedfrom biomass into an organic acid.

FIG. 2 is a schematic diagram illustrating a process for making ethanol.

FIG. 3 is a schematic diagram illustrating another process for makingethanol.

FIG. 4 is a schematic diagram illustrating another process for makingethanol.

FIG. 5 is a schematic diagram illustrating another process for makingethanol.

FIG. 6 is a schematic diagram illustrating another process for makingethanol.

FIG. 7 is a schematic diagram illustrating utilizing biologicalconversion residue in a process for making ethanol.

FIG. 7A is a schematic diagram illustrating conversion of calciumacetate and ethanol to ethyl acetate.

FIG. 8 is a schematic diagram illustrating production of propyleneglycol.

FIG. 9 is a schematic drawing illustrating carbon capture in variousgeological formations.

FIG. 10 is a schematic drawing illustrating photosynthesis ofcarbohydrates and lipids.

FIG. 11 is a schematic drawing illustrating production of bio-diesel.

FIG. 12 is a schematic drawing a fuel production process utilizingalgae, while FIG. 12A is an enlarged view of region 12.

DETAILED DESCRIPTION

Carbon-containing materials, such as biomass (e.g., coal, plant biomass,animal biomass, and municipal waste biomass) can be processed to a lowerlevel of recalcitrance (if necessary) and converted into useful productssuch as organic acids, salts of organic acids, anhydrides, esters oforganic acids and fuels, e.g., fuels for internal combustion engines orfeedstocks for fuel cells. Systems and processes are described hereinthat use readily abundant, but often difficult to process, materials,such as pre-coal or coal, e.g., peat, lignite, sub-bituminous,bituminous and anthracite, oil sand, oil shale or cellulosic orlignocellulosic materials. Many of the processes described herein caneffectively lower the recalcitrance level of any carbon-containingmaterial, such as any carbon-containing material described herein,making it easier to process, such as by bioprocessing (e.g., with anymicroorganism described herein, such as a homoacetogen or aheteroacetogen, and/or any enzyme described herein), thermal processing(e.g., gasification, cracking or pyrolysis) or chemical methods (e.g.,acid hydrolysis or oxidation). Generally, if required, materials can bephysically treated for processing and/or after processing, often by sizereduction. Physically processed feedstock can be treated or processedusing one or more of any of the methods described herein, such asradiation, sonication, oxidation, pyrolysis or steam explosion. Thevarious treatment systems and methods can be used in combinations oftwo, three, or even four of these technologies or others describedherein and elsewhere.

In some cases, to provide materials that include a carbohydrate, such ascellulose or hemicellulose, that can be converted by a microorganism toa number of desirable products, such as a combustible fuels (e.g.,ethanol, butanol or hydrogen), organic acids or anhydrides, feedstocksthat include one or more saccharide units can be treated by any one ormore of the processes described herein. Other products and co-productsthat can be produced include, e.g., human food, animal feed,pharmaceuticals, and nutriceuticals. When organic acids are preparedfirst, such acids can be converted to other intermediates (e.g., estersand anhydrides), and then converted to alcohols by hydrogenation, e.g.,high-pressure hydrogenation, such as at a pressure of between about 25bar and 700 bar, e.g., 50 to 500 bar, or 100 to 400 bar, in the presenceof a catalyst, such as copper chromite catalyst, cobalt catalysts, zinccatalysts or palladium catalysts. Hydrogenation of esters is discussedin Wall, R. G., U.S. Pat. No. 4,113,662. Preparing organic acids canhave benefits relative to making alcohols directly in some instances(e.g., in terms of carbon utilization efficiency), as will be describedfurther herein. In some embodiments, acetogens or homoacetogens, whichare capable of utilizing a syngas from a thermochemical conversionprocess, can be utilized to enhance the efficiency of the conversion.

Referring to FIG. 1, in some instances and when necessary, a firstmaterial, such as a lignocellulosic material, having a first level ofrecalcitrance is processed, such as by treating with a beam ofparticles, such as electrons, to produce a second material having asecond level of recalcitrance lower than the first level ofrecalcitrance. At this point and if necessary, the second material canbe hydrolyzed, e.g., using enzymes, to its constituent sugars, such asglucose, xylose and arabinose. Referring now to FIGS. 1A and 1Bcollectively, the sugars can be converted directly into an alcohol by amicroorganism, such as a one or more bacteria or yeasts, such asSaccharomyces cerevisiae and/or Pichia stipitis, or the sugars can beconverted to an organic acid, such as acetic acid and/or lactic acid. Ifdesired, the organic acid can be converted to an ester, and then theester hydrogenated under a high pressure of hydrogen and in the presenceof a catalyst to liberate alcohol.

Examples of Biomass

Generally, any biomass material that is or includes carbohydratescomposed entirely of one or more saccharide units or that includes oneor more saccharide units can be processed by any of the methodsdescribed herein, such as being processed to reduce its level ofrecalcitrance. For example, the biomass material can include one or morecellulosic or lignocellulosic materials, or starchy materials, such askernels of corn, grains of rice or other foods.

For example, such materials can include paper, paper products, wood,wood-related materials, particle board, grasses, rice hulls, bagasse,cotton, jute, hemp, flax, bamboo, sisal, abaca, straw, corn cobs, ricehulls, coconut hair, algae, seaweed, cotton, synthetic celluloses, ormixtures of any of these.

For example, the biomass can be fibrous in nature. Fiber sources includecellulosic fiber sources, including paper and paper products (e.g.,polycoated paper and Kraft paper), and lignocellulosic fiber sources,including wood, and wood-related materials, e.g., particle board. Othersuitable fiber sources include natural fiber sources, e.g., grasses,rice hulls, bagasse, cotton, jute, hemp, flax, bamboo, sisal, abaca,straw, corn cobs, rice hulls, coconut hair; fiber sources high inα-cellulose content, e.g., cotton. Fiber sources can be obtained fromvirgin scrap textile materials, e.g., remnants, post consumer waste,e.g., rags. When paper products are used as fiber sources, they can bevirgin materials, e.g., scrap virgin materials, or they can bepost-consumer waste. Aside from virgin raw materials, post-consumer,industrial (e.g., offal), and processing waste (e.g., effluent frompaper processing) can also be used as fiber sources. Also, the fibersource can be obtained or derived from human (e.g., sewage), animal orplant wastes. Additional fiber sources have been described in U.S. Pat.Nos. 6,448,307, 6,258,876, 6,207,729, 5,973,035 and 5,952,105.

In some embodiments, the carbohydrate is or includes a material havingone or more β-1,4-linkages and having a number average molecular weightbetween about 3,000 and 50,000. Such a carbohydrate is or includescellulose (I), which is derived from (β-glucose 1) through condensationof β(1,4)-glycosidic bonds. This linkage contrasts itself with that forα(1,4)-glycosidic bonds present in starch and other carbohydrates.

Starchy materials include starch itself, e.g., corn starch, wheatstarch, potato starch or rice starch, a derivative of starch, or amaterial that includes starch, such as an edible food product or a crop.For example, the starchy material can be arracacha, buckwheat, banana,barley, cassaya, kudzu, oca, sago, sorghum, regular household potatoes,sweet potato, taro, yams, or one or more beans, such as favas, lentilsor peas. Blends of any two or more starchy materials are also starchymaterials. In particular embodiments, the starchy material is derivedfrom corn. Various corn starches and derivatives are described in “CornStarch,” Corn Refiners Association (11^(th) Edition, 2006).

Examples of Other Carbon-Containing Materials and Blends

Pre-coal or coal, e.g., peat, lignite, sub-bituminous, bituminous andanthracite, oil sand, oil shale can also be utilized as carbon sources.In addition, blends of any biomass materials described herein and anyother carbon-containing material described herein can be utilized formaking any of the products described herein, such as ethanol, aceticacid or ethyl acetate.

Physical Preparation

In some cases, methods can include a physical preparation, e.g., sizereduction of materials, such as by cutting, grinding, shearing,pulverizing or chopping. For example, in some cases, loose feedstock(e.g., recycled paper, starchy materials, coal or switchgrass) isprepared by shearing or shredding. For example, in other cases, materialis first pretreated or processed using one or more any of the methodsdescribed herein, such as radiation, sonication, oxidation, pyrolysis orsteam explosion, and then size reduced or further size reduced. Treatingfirst and then size reducing can be advantageous since treated materialstend to be more brittle and, therefore, easier to size reduce. Screensand/or magnets can be used to remove oversized or undesirable objectssuch as, for example, rocks or nails from the feed stream.

Feed preparation systems can be configured to produce streams withspecific characteristics such as, for example, specific maximum sizes,specific length-to-width, or specific surface areas ratios. Physicalpreparation can increase the rate of reactions or reduce the processingtime required by opening up the materials and making them moreaccessible to processes and/or reagents, such as reagents in a solution.The bulk density of feedstocks can be controlled (e.g., increased). Insome situations, it can be desirable to prepare a low bulk densitymaterial, densify the material (e.g., to make it easier and less costlyto transport to another site), and then revert the material to a lowerbulk density state.

Size Reduction

In some embodiments, the material to be processed is in the form of afibrous material that includes fibers provided by shearing a fibersource. For example, the shearing can be performed with a rotary knifecutter.

For example, a fiber source, e.g., that is recalcitrant or that has hadits recalcitrance level reduced, can be sheared, e.g., in a rotary knifecutter, to provide a first fibrous material. The first fibrous materialis passed through a first screen, e.g., having an average opening sizeof 1.59 mm or less ( 1/16 inch, 0.0625 inch), provide a second fibrousmaterial. If desired, the fiber source can be cut prior to the shearing,e.g., with a shredder. For example, when a paper is used as the fibersource, the paper can be first cut into strips that are, e.g., ¼- to½-inch wide, using a shredder, e.g., a counter-rotating screw shredder,such as those manufactured by Munson (Utica, N.Y.). As an alternative toshredding, the paper can be reduced in size by cutting to a desired sizeusing a guillotine cutter. For example, the guillotine cutter can beused to cut the paper into sheets that are, e.g., 10 inches wide by 12inches long.

In some embodiments, the shearing of the fiber source and the passing ofthe resulting first fibrous material through a first screen areperformed concurrently. The shearing and the passing can also beperformed in a batch-type process.

For example, a rotary knife cutter can be used to concurrently shear thefiber source and screen the first fibrous material. A rotary knifecutter includes a hopper that can be loaded with a shredded fiber sourceprepared by shredding a fiber source. The shredded fiber source issheared between stationary blades and rotating blades to provide a firstfibrous material. The first fibrous material passes through a screen,and the resulting second fibrous material is captured in a bin. To aidin the collection of the second fibrous material, the bin can have apressure below nominal atmospheric pressure, e.g., at least 10 percentbelow nominal atmospheric pressure, e.g., at least 25 percent belownominal atmospheric pressure, at least 50 percent below nominalatmospheric pressure, or at least 75 percent below nominal atmosphericpressure. In some embodiments, a vacuum source is utilized to maintainthe bin below nominal atmospheric pressure.

Shearing can be advantageous for “opening up” and “stressing” thefibrous materials, making the cellulose of the materials moresusceptible to chain scission and/or reduction of crystallinity. Theopen materials can also be more susceptible to oxidation whenirradiated.

The fiber source can be sheared in a dry state (e.g., having little orno free water on its surface), a hydrated state (e.g., having up to tenpercent by weight absorbed water), or in a wet state, e.g., havingbetween about 10 percent and about 75 percent by weight water. The fibersource can even be sheared while partially or fully submerged under aliquid, such as water, ethanol or isopropanol.

The fiber source can also be sheared under a gas (such as a stream oratmosphere of gas other than air), e.g., oxygen or nitrogen, or steam.

Other methods of making the fibrous materials include, e.g., stonegrinding, mechanical ripping or tearing, pin grinding or air attritionmilling.

If desired, the fibrous materials can be separated, e.g., continuouslyor in batches, into fractions according to their length, width, density,material type, or some combination of these attributes. For example, forforming composites, it is often desirable to have a relatively narrowdistribution of fiber lengths.

The fibrous materials can also be separated, e.g., by using a highvelocity gas, e.g., air. In such an approach, the fibrous materials areseparated by drawing off different fractions, which can be characterizedphotonically, if desired. Such a separation apparatus is discussed inLindsey et al, U.S. Pat. No. 6,883,667.

Ferrous materials can be separated from any of the fibrous materials bypassing a fibrous material that includes a ferrous material past amagnet, e.g., an electromagnet, and then passing the resulting fibrousmaterial through a series of screens, each screen having different sizedapertures.

The fibrous materials can be irradiated immediately following theirpreparation, or they can may be dried, e.g., at approximately 105° C.for 4-18 hours, so that the moisture content is, e.g., less than about0.5% before use.

If desired, lignin can be removed from any of the fibrous materials thatinclude lignin. Also, to aid in the breakdown of the materials thatinclude cellulose, the material can be treated prior to irradiation withheat, a chemical (e.g., mineral acid, base or a strong oxidizer such assodium hypochlorite) and/or an enzyme.

In some embodiments, the average opening size of the first screen isless than 0.79 mm ( 1/32 inch, 0.03125 inch), e.g., less than 0.51 mm (1/50 inch, 0.02000 inch), less than 0.40 mm ( 1/64 inch, 0.015625 inch),less than 0.23 mm (0.009 inch), less than 0.20 mm ( 1/128 inch,0.0078125 inch), less than 0.18 mm (0.007 inch), less than 0.13 mm(0.005 inch), or even less than less than 0.10 mm ( 1/256 inch,0.00390625 inch). The screen can be prepared, e.g., by interweavingmonofilaments having an appropriate diameter to give the desired openingsize. For example, the monofilaments can be made of a metal, e.g.,stainless steel. As the opening sizes get smaller, structural demands onthe monofilaments may become greater. For example, for opening sizesless than 0.40 mm, it can be advantageous to make the screens frommonofilaments made from a material other than stainless steel, e.g.,titanium, titanium alloys, amorphous metals, nickel, tungsten, rhodium,rhenium, ceramics, or glass. In some embodiments, the screen is madefrom a plate, e.g. a metal plate, having apertures, e.g., cut into theplate using a laser. In some embodiments, the open area of the mesh isless than 52%, e.g., less than 41%, less than 36%, less than 31% or lessthan 30%.

A third fibrous material can be prepared from the second fibrousmaterial by shearing the second fibrous material and passing theresulting material through a second screen having an average openingsize less than the first screen.

Generally, the fibers of the fibrous materials can have a relativelylarge average length-to-diameter ratio (e.g., greater than 20-to-1),even if they have been sheared more than once. In addition, the fibersof the fibrous materials described herein may have a relatively narrowlength and/or length-to-diameter ratio distribution.

As used herein, average fiber widths (e.g., diameters) are thosedetermined optically by randomly selecting approximately 5,000 fibers.Average fiber lengths are corrected length-weighted lengths. BET(Brunauer, Emmet and Teller) surface areas are multi-point surfaceareas, and porosities are those determined by mercury porosimetry.

The average length-to-diameter ratio of the second fibrous material 14can be, e.g. greater than 8/1, e.g., greater than 10/1, greater than15/1, greater than 20/1, greater than 25/1, or greater than 50/1. Anaverage length of the second fibrous material 14 can be, e.g., betweenabout 0.5 mm and 2.5 mm, e.g., between about 0.75 mm and 1.0 mm, and anaverage width (e.g., diameter) of the second fibrous material 14 can be,e.g., between about 5 μm and 50 μm, e.g., between about 10 μm and 30 μm.

In some embodiments, a standard deviation of the length of the secondfibrous material 14 is less than 60 percent of an average length of thesecond fibrous material 14, e.g., less than 50 percent of the averagelength, less than 40 percent of the average length, less than 25 percentof the average length, less than 10 percent of the average length, lessthan 5 percent of the average length, or even less than 1 percent of theaverage length.

In some embodiments, a BET surface area of the second fibrous materialis greater than 0.1 m²/g, e.g., greater than 0.25 m²/g, greater than 0.5m²/g, greater than 1.0 m²/g, greater than 1.5 m²/g, greater than 1.75m²/g, greater than 5.0 m²/g, greater than 10 m²/g, greater than 25 m²/g,greater than 35 m²/g, greater than 50 m²/g, greater than 60 m²/g,greater than 75 m²/g, greater than 100 m²/g, greater than 150 m²/g,greater than 200 m²/g, or even greater than 250 m²/g.

A porosity of the second fibrous material can be, e.g., greater than 20percent, greater than 25 percent, greater than 35 percent, greater than50 percent, greater than 60 percent, greater than 70 percent, greaterthan 80 percent, greater than 85 percent, greater than 90 percent,greater than 92 percent, greater than 94 percent, greater than 95percent, greater than 97.5 percent, greater than 99 percent, or evengreater than 99.5 percent.

In some embodiments, a ratio of the average length-to-diameter ratio ofthe first fibrous material to the average length-to-diameter ratio ofthe second fibrous material is, e.g., less than 1.5, less than 1.4, lessthan 1.25, less than 1.1, less than 1.075, less than 1.05, less than1.025, or even substantially equal to 1.

In particular embodiments, the second fibrous material is sheared againand the resulting fibrous material passed through a second screen havingan average opening size less than that of the first screen to provide athird fibrous material. In such instances, a ratio of the averagelength-to-diameter ratio of the second fibrous material to the averagelength-to-diameter ratio of the third fibrous material can be, e.g.,less than 1.5, e.g., less than 1.4, less than 1.25, or even less than1.1.

In some embodiments, the third fibrous material is passed through athird screen to produce a fourth fibrous material. The fourth fibrousmaterial can be, e.g., passed through a fourth screen to produce a fifthmaterial. Similar screening processes can be repeated as many times asdesired to produce the desired fibrous material having the desiredproperties.

Densification

Densified materials can be processed by any of the methods describedherein, or any material processed by any of the methods described hereincan be subsequently densified.

A material, e.g., a processed or unprocessed fibrous material, having alow bulk density can be densified to a product having a higher bulkdensity. For example, a material composition having a bulk density of0.05 g/cm³ can be densified by sealing the fibrous material in arelatively gas impermeable structure, e.g., a bag made of polyethylene,a bag made of alternating layers of polyethylene and a nylon, or a bagmade of a dissolvable material such as a starch-based film, and thenevacuating the entrapped gas, e.g., air, from the structure. Afterevacuation of the air from the structure, the fibrous material can havea bulk density of, e.g., greater than 0.3 g/cm³, 0.5 g/cm³, 0.6 g/cm³,0.7 g/cm³ or more, e.g., 0.85 g/cm³. Prior to and/or afterdensification, the product can be processed by any of the methodsdescribed herein, such as irradiated, e.g., with gamma radiation. Thiscan be advantageous when it is desirable to transport the material toanother location, e.g., a remote manufacturing plant, where the fibrousmaterial composition can be added to a solution, e.g., to produceethanol. After cutting or piercing the substantially gas impermeablestructure, the densified fibrous material can revert to nearly itsinitial bulk density, e.g., greater than 60 percent of its initial bulkdensity, e.g., 70 percent, 80 percent, 85 percent or more, e.g., 95percent of its initial bulk density. To reduce static electricity in thefibrous material, an anti-static agent can be added to the material.

In some embodiments, the structure, e.g., bag, is formed of a materialthat dissolves in a liquid, such as water. For example, the structurecan be formed from a polyvinyl alcohol so that it dissolves when incontact with a water-based system. Such embodiments allow densifiedstructures to be added directly to solutions that include amicroorganism, without first releasing the contents of the structure,e.g., by cutting or piercing.

Any material, e.g., biomass material, can be combined with any desiredadditives and a binder, and subsequently densified by application ofpressure, e.g., by passing the material through a nip defined betweencounter-rotating pressure rolls or by passing the material through apellet mill. During the application of pressure, heat can optionally beapplied to aid in the densification of the fibrous material. Thedensified material can then be irradiated.

In some embodiments, the material prior to densification has a bulkdensity of less than 0.25 g/cm³, e.g., 0.20 g/cm³, 0.15 g/cm³, 0.10g/cm³, 0.05 g/cm³ or less, e.g., 0.025 g/cm³. Bulk density is determinedusing ASTM D1895B. Briefly, the method involves filling a measuringcylinder of known volume with a sample and obtaining a weight of thesample. The bulk density is calculated by dividing the weight of thesample in grams by the known volume of the cylinder in cubiccentimeters.

The preferred binders include binders that are soluble in water, swollenby water, or that have a glass transition temperature of less than 25°C., as determined by differential scanning calorimetry. By water-solublebinders, we mean binders having a solubility of at least about 0.05weight percent in water. By water swellable binders, we mean bindersthat increase in volume by more than 0.5 percent upon exposure to water.

In some embodiments, the binders that are soluble or swollen by waterinclude a functional group that is capable of forming a bond, e.g., ahydrogen bond, with the fibers of the fibrous material, e.g., cellulosicfibrous material. For example, the functional group can be a carboxylicacid group, a carboxylate group, a carbonyl group, e.g., of an aldehydeor a ketone, a sulfonic acid group, a sulfonate group, a phosphoric acidgroup, a phosphate group, an amide group, an amine group, a hydroxylgroup, e.g., of an alcohol, and combinations of these groups, e.g., acarboxylic acid group and a hydroxyl group. Specific monomeric examplesinclude glycerin, glyoxal, ascorbic acid, urea, glycine,pentaerythritol, a monosaccharide or a disaccharide, citric acid, andtartaric acid. Suitable saccharides include glucose, sucrose, lactose,ribose, fructose, mannose, arabinose and erythrose. Polymeric examplesinclude polyglycols, polyethylene oxide, polycarboxylic acids,polyamides, polyamines and polysulfonic acids and polysulfonates.Specific polymeric examples include polypropylene glycol (PPG),polyethylene glycol (PEG), polyethylene oxide, e.g., POLYOX®, copolymersof ethylene oxide and propylene oxide, polyacrylic acid (PAA),polyacrylamide, polypeptides, polyethylenimine, polyvinylpyridine,poly(sodium-4-styrenesulfonate) andpoly(2-acrylamido-methyl-1-propanesulfonic acid).

In some embodiments, the binder includes a polymer that has a glasstransition temperature of less 25° C. Examples of such polymers includethermoplastic elastomers (TPEs). Examples of TPEs include polyetherblock amides, such as those available under the tradename PEBAX®,polyester elastomers, such as those available under the tradenameHYTREL®, and styrenic block copolymers, such as those available underthe tradename KRATON®. Other suitable polymers having a glass transitiontemperature less 25° C. include ethylene vinyl acetate copolymer (EVA),polyolefins, e.g., polyethylene, polypropylene, ethylene-propylenecopolymers, and copolymers of ethylene and alpha olefins, e.g.,1-octene, such as those available under the tradename ENGAGE®.

In a particular embodiment, the binder is a lignin, e.g., a natural orsynthetically modified lignin.

A suitable amount of binder added to the material, calculated on a dryweight basis, is, e.g., from about 0.01 percent to about 50 percent,e.g., 0.03 percent, 0.05 percent, 0.1 percent, 0.25 percent, 0.5percent, 1.0 percent, 5 percent, 10 percent or more, e.g., 25 percent,based on a total weight of the densified material. The binder can beadded to the material as a neat, pure liquid, as a liquid having thebinder dissolved therein, as a dry powder of the binder, or as pelletsof the binder.

The densified fibrous material can be made in a pellet mill. Thematerial, after densification, can be conveniently in the form ofpellets or chips having a variety of shapes. The pellets can then beirradiated or otherwise treated by any method described herein. In someembodiments, the pellets or chips are cylindrical in shape, e.g., havinga maximum transverse dimension of, e.g., 1 mm or more, e.g., 2 mm, 3 mm,5 mm, 8 mm, 10 mm, 15 mm or more, e.g., 25 mm. Pellets can be made sothat they have a hollow inside. The hollow can be generally in-line withthe center of the pellet, or out of line with the center of the pellet.Making the pellet hollow inside can increase the rate of dissolution ina liquid.

The pellet can have, e.g., a transverse shape that is multi-lobal, e.g.,tri-lobal as shown, or tetra-lobal, penta-lobal, hexa-lobal ordeca-lobal. Making the pellets in such transverse shapes can alsoincrease the rate of dissolution in a solution.

Treatment to Solubilize, Reduce Recalcitrance or to Functionalize

Materials that have or have not been physically prepared can be treatedfor use in any production process described herein. Treatment processescan include one or more of any of those described herein, such asirradiation, sonication, oxidation, pyrolysis or steam explosion.Treatment methods can be used in combinations of two, three, four, oreven all of these technologies (in any order).

Radiation Treatment

One or more radiation processing sequences can be used to processmaterials from a wide variety of different sources to extract usefulsubstances from the feedstock, and to provide partially degraded organicmaterial, which functions as input to further processing steps and/orsequences. Irradiation can reduce the molecular weight and/orcrystallinity and/or recalcitrance of a feedstock. In some embodiments,energy deposited in a material that releases an electron from its atomicorbital is used to irradiate the materials. The radiation may beprovided by 1) heavy charged particles, such as alpha particles orprotons, 2) electrons, produced, for example, in beta decay or electronbeam accelerators, or 3) electromagnetic radiation, for example, gammarays, x rays, or ultraviolet rays. In one approach, radiation producedby radioactive substances can be used to irradiate the feedstock. Insome embodiments, any combination in any order or concurrently of (1)through (3) may be utilized. In another approach, electromagneticradiation (e.g., produced using electron beam emitters) can be used toirradiate the feedstock.

The doses applied depend on the desired effect and the particularfeedstock. For example, high doses of radiation can break chemical bondswithin feedstock components. In some instances when chain scission isdesirable and/or polymer chain functionalization is desirable, particlesheavier than electrons, such as protons, helium nuclei, argon ions,silicon ions, neon ions, carbon ions, phosphorus ions, oxygen ions ornitrogen ions can be utilized. When ring-opening chain scission isdesired, positively charged particles can be utilized for their Lewisacid properties for enhanced ring-opening chain scission. For example,when maximum oxidation is desired, oxygen ions can be utilized, and whenmaximum nitration is desired, nitrogen ions can be utilized.

In one method, a first material that is or includes cellulose having afirst number average molecular weight (M_(N1)) is irradiated, e.g., bytreatment with ionizing radiation (e.g., in the form of gamma radiation,X-ray radiation, 100 nm to 280 nm ultraviolet (UV) light, a beam ofelectrons or other charged particles) to provide a second material thatincludes cellulose having a second number average molecular weight(M_(N2)) lower than the first number average molecular weight. Thesecond material (or the first and second material) can be combined witha microorganism (with or without enzyme treatment) that can utilize thesecond and/or first material or its constituent sugars or lignin toproduce a fuel or other useful product that is or includes hydrogen, analcohol (e.g., ethanol or butanol, such as n-, sec- or t-butanol), anorganic acid, a hydrocarbon or mixtures of any of these.

Since the second material has cellulose having a reduced molecularweight relative to the first material, and in some instances, a reducedcrystallinity as well, the second material is generally moredispersible, swellable and/or soluble in a solution containing amicroorganism and/or an enzyme. These properties make the secondmaterial more susceptible to chemical, enzymatic and/or biologicalattack relative to the first material, which can greatly improve theproduction rate and/or production level of a desired product, e.g.,ethanol. Radiation can also sterilize the materials or any media neededto bioprocess the material.

In some embodiments, the second number average molecular weight (M_(N2))is lower than the first number average molecular weight (M_(N1)) by morethan about 10 percent, e.g., 15, 20, 25, 30, 35, 40, 50 percent, 60percent, or even more than about 75 percent.

In some instances, the second material has cellulose that has ascrystallinity (C₂) that is lower than the crystallinity (C₁) of thecellulose of the first material. For example, (C₂) can be lower than(C₁) by more than about 10 percent, e.g., 15, 20, 25, 30, 35, 40, oreven more than about 50 percent.

In some embodiments, the starting crystallinity index (prior toirradiation) is from about 40 to about 87.5 percent, e.g., from about 50to about 75 percent or from about 60 to about 70 percent, and thecrystallinity index after irradiation is from about 10 to about 50percent, e.g., from about 15 to about 45 percent or from about 20 toabout 40 percent. However, in some embodiments, e.g., after extensiveirradiation, it is possible to have a crystallinity index of lower than5 percent. In some embodiments, the material after irradiation issubstantially amorphous.

In some embodiments, the starting number average molecular weight (priorto irradiation) is from about 200,000 to about 3,200,000, e.g., fromabout 250,000 to about 1,000,000 or from about 250,000 to about 700,000,and the number average molecular weight after irradiation is from about50,000 to about 200,000, e.g., from about 60,000 to about 150,000 orfrom about 70,000 to about 125,000. However, in some embodiments, e.g.,after extensive irradiation, it is possible to have a number averagemolecular weight of less than about 10,000 or even less than about5,000.

In some embodiments, the second material can have a level of oxidation(O₂) that is higher than the level of oxidation (O₁) of the firstmaterial. A higher level of oxidation of the material can aid in itsdispersability, swellability and/or solubility, further enhancing thematerial's susceptibility to chemical, enzymatic or biological attack.In some embodiments, to increase the level of the oxidation of thesecond material relative to the first material, the irradiation isperformed under an oxidizing environment, e.g., under a blanket of airor oxygen, producing a second material that is more oxidized than thefirst material. For example, the second material can have more hydroxylgroups, aldehyde groups, ketone groups, ester groups or carboxylic acidgroups, which can increase its hydrophilicity.

Ionizing Radiation

Each form of radiation ionizes the carbon-containing material viaparticular interactions, as determined by the energy of the radiation.Heavy charged particles primarily ionize matter via Coulomb scattering;furthermore, these interactions produce energetic electrons that mayfurther ionize matter. Alpha particles are identical to the nucleus of ahelium atom and are produced by the alpha decay of various radioactivenuclei, such as isotopes of bismuth, polonium, astatine, radon,francium, radium, several actinides, such as actinium, thorium, uranium,neptunium, curium, californium, americium, and plutonium.

When particles are utilized, they can be neutral (uncharged), positivelycharged or negatively charged. When charged, the charged particles canbear a single positive or negative charge, or multiple charges, e.g.,one, two, three or even four or more charges. In instances in whichchain scission is desired, positively charged particles may bedesirable, in part due to their acidic nature. When particles areutilized, the particles can have the mass of a resting electron, orgreater, e.g., 500, 1000, 1500, 2000, 10,000 or even 100,000 times themass of a resting electron. For example, the particles can have a massof from about 1 atomic unit to about 150 atomic units, e.g., from about1 atomic unit to about 50 atomic units, or from about 1 to about 25,e.g., 1, 2, 3, 4, 5, 10, 12 or 15 amu. Accelerators used to acceleratethe particles can be electrostatic DC, electrodynamic DC, RF linear,magnetic induction linear or continuous wave. For example, cyclotrontype accelerators are available from IBA, Belgium, such as theRhodatron® system, while DC type accelerators are available from RDI,now IBA Industrial, such as the Dynamitron®. Ions and ion acceleratorsare discussed in Introductory Nuclear Physics, Kenneth S. Krane, JohnWiley & Sons, Inc. (1988), Krsto Prelec, FIZIKA B 6 (1997) 4, 177-206,Chu, William T., “Overview of Light-Ion Beam Therapy” Columbus-Ohio,ICRU-IAEA Meeting, 18-20 Mar. 2006, Iwata, Y. et al.,“Alternating-Phase-Focused 1H-DTL for Heavy-Ion Medical Accelerators”Proceedings of EPAC 2006, Edinburgh, Scotland and Leaner, C. M. et al.,“Status of the Superconducting ECR Ion Source Venus” Proceedings of EPAC2000, Vienna, Austria.

Gamma radiation has the advantage of a significant penetration depthinto a variety of materials. Sources of gamma rays include radioactivenuclei, such as isotopes of cobalt, calcium, technicium, chromium,gallium, indium, iodine, iron, krypton, samarium, selenium, sodium,thalium, and xenon.

Sources of x rays include electron beam collision with metal targets,such as tungsten or molybdenum or alloys, or compact light sources, suchas those produced commercially by Lyncean.

Sources for ultraviolet radiation include deuterium or cadmium lamps.

Sources for infrared radiation include sapphire, zinc, or selenidewindow ceramic lamps.

Sources for microwaves include klystrons, Slevin type RF sources, oratom beam sources that employ hydrogen, oxygen, or nitrogen gases.

In some embodiments, a beam of electrons is used as the radiationsource. A beam of electrons has the advantages of high dose rates (e.g.,1, 5, or even 10 Mrad per second), high throughput, less containment,and less confinement equipment. Electrons can also be more efficient atcausing chain scission. In addition, electrons having energies of 4-10MeV can have a penetration depth of 5 to 30 mm or more, such as 40 mm.

Electron beams can be generated, e.g., by electrostatic generators,cascade generators, transformer generators, low energy accelerators witha scanning system, low energy accelerators with a linear cathode, linearaccelerators, and pulsed accelerators. Electrons as an ionizingradiation source can be useful, e.g., for relatively thin piles ofmaterials, e.g., less than 0.5 inch, e.g., less than 0.4 inch, 0.3 inch,0.2 inch, or less than 0.1 inch. In some embodiments, the energy of eachelectron of the electron beam is from about 0.3 MeV to about 2.0 MeV(million electron volts), e.g., from about 0.5 MeV to about 1.5 MeV, orfrom about 0.7 MeV to about 1.25 MeV.

Electron beam irradiation devices may be procured commercially from IonBeam Applications, Louvain-la-Neuve, Belgium or the Titan Corporation,San Diego, Calif. Typical electron energies can be 1 MeV, 2 MeV, 4.5MeV, 7.5 MeV, or 10 MeV. Typical electron beam irradiation device powercan be 1 kW, 5 kW, 10 kW, 20 kW, 50 kW, 100 kW, 250 kW, or 500 kW. Thelevel of depolymerization of the feedstock depends on the electronenergy used and the dose applied, while exposure time depends on thepower and dose. Typical doses may take values of 1 kGy, 5 kGy, 10 kGy,20 kGy, 50 kGy, 100 kGy, or 200 kGy.

Ion Particle Beams

Particles heavier than electrons can be utilized to irradiate materials,such as carbohydrates or materials that include carbohydrates, e.g.,cellulosic materials, lignocellulosic materials, starchy materials, ormixtures of any of these and others described herein. For example,protons, helium nuclei, argon ions, silicon ions, neon ions carbon ions,phosphorus ions, oxygen ions or nitrogen ions can be utilized. In someembodiments, particles heavier than electrons can induce higher amountsof chain scission (relative to lighter particles). In some instances,positively charged particles can induce higher amounts of chain scissionthan negatively charged particles due to their acidity.

Heavier particle beams can be generated, e.g., using linear acceleratorsor cyclotrons. In some embodiments, the energy of each particle of thebeam is from about 1.0 MeV/atomic unit to about 6,000 MeV/atomic unit,e.g., from about 3 MeV/atomic unit to about 4,800 MeV/atomic unit, orfrom about 10 MeV/atomic unit to about 1,000 MeV/atomic unit.

In certain embodiments, ion beams used to irradiate carbon-containingmaterials, e.g., biomass materials, can include more than one type ofion. For example, ion beams can include mixtures of two or more (e.g.,three, four or more) different types of ions. Exemplary mixtures caninclude carbon ions and protons, carbon ions and oxygen ions, nitrogenions and protons, and iron ions and protons. More generally, mixtures ofany of the ions discussed above (or any other ions) can be used to formirradiating ion beams. In particular, mixtures of relatively light andrelatively heavier ions can be used in a single ion beam.

In some embodiments, ion beams for irradiating materials includepositively-charged ions. The positively charged ions can include, forexample, positively charged hydrogen ions (e.g., protons), noble gasions (e.g., helium, neon, argon), carbon ions, nitrogen ions, oxygenions, silicon atoms, phosphorus ions, and metal ions such as sodiumions, calcium ions, and/or iron ions. Without wishing to be bound by anytheory, it is believed that such positively-charged ions behavechemically as Lewis acid moieties when exposed to materials, initiatingand sustaining cationic ring-opening chain scission reactions in anoxidative environment.

In certain embodiments, ion beams for irradiating materials includenegatively-charged ions. Negatively charged ions can include, forexample, negatively charged hydrogen ions (e.g., hydride ions), andnegatively charged ions of various relatively electronegative nuclei(e.g., oxygen ions, nitrogen ions, carbon ions, silicon ions, andphosphorus ions). Without wishing to be bound by any theory, it isbelieved that such negatively-charged ions behave chemically as Lewisbase moieties when exposed to materials, causing anionic ring-openingchain scission reactions in a reducing environment.

In some embodiments, beams for irradiating materials can include neutralatoms. For example, any one or more of hydrogen atoms, helium atoms,carbon atoms, nitrogen atoms, oxygen atoms, neon atoms, silicon atoms,phosphorus atoms, argon atoms, and iron atoms can be included in beamsthat are used for irradiation of biomass materials. In general, mixturesof any two or more of the above types of atoms (e.g., three or more,four or more, or even more) can be present in the beams.

In certain embodiments, ion beams used to irradiate materials includesingly-charged ions such as one or more of H⁺, H⁻, He⁺, Ne⁺, Ar⁺, C⁺,C⁻, O⁺, O⁻, N⁺, N⁻, Si⁺, Si⁻, P⁺, P⁻, Na⁺, Ca⁺, and Fe⁺. In someembodiments, ion beams can include multiply-charged ions such as one ormore of C²⁺, C³⁺, C⁴⁺, N³⁺, N⁵⁺, N³⁻, O²⁺, O²⁻, O₂ ²⁻, Si²⁺, Si⁴⁺, Si²⁻,and Si⁴⁻. In general, the ion beams can also include more complexpolynuclear ions that bear multiple positive or negative charges. Incertain embodiments, by virtue of the structure of the polynuclear ion,the positive or negative charges can be effectively distributed oversubstantially the entire structure of the ions. In some embodiments, thepositive or negative charges can be somewhat localized over portions ofthe structure of the ions.

Electromagnetic Radiation

In embodiments in which the irradiating is performed withelectromagnetic radiation, the electromagnetic radiation can have, e.g.,energy per photon (in electron volts) of greater than 10² eV, e.g.,greater than 10³, 10⁴, 10⁵, 10⁶, or even greater than 10⁷ eV. In someembodiments, the electromagnetic radiation has energy per photon ofbetween 10⁴ and 10⁷, e.g., between 10⁵ and 10⁶ eV. The electromagneticradiation can have a frequency of, e.g., greater than 10¹⁶ hz, greaterthan 10¹⁷ hz, 10¹⁸, 10¹⁹, 10²⁰, or even greater than 10²¹ hz. In someembodiments, the electromagnetic radiation has a frequency of between10¹⁸ and 10²² hz, e.g., between 10¹⁹ to 10²¹ hz.

Doses

In some embodiments, the irradiating (with any radiation source or acombination of sources) is performed until the material receives a doseof at least 0.25 Mrad, e.g., at least 1.0 Mrad, at least 2.5 Mrad, atleast 5.0 Mrad, or at least 10.0 Mrad. In some embodiments, theirradiating is performed until the material receives a dose of between1.0 Mrad and 6.0 Mrad, e.g., between 1.5 Mrad and 4.0 Mrad.

In some embodiments, the irradiating is performed at a dose rate ofbetween 5.0 and 1500.0 kilorads/hour, e.g., between 10.0 and 750.0kilorads/hour or between 50.0 and 350.0 kilorads/hours.

In some embodiments, two or more radiation sources are used, such as twoor more ionizing radiations. For example, samples can be treated, in anyorder, with a beam of electrons, followed by gamma radiation and UVlight having wavelengths from about 100 nm to about 280 nm. In someembodiments, samples are treated with three ionizing radiation sources,such as a beam of electrons, gamma radiation, and energetic UV light.

Sonication

One or more sonication processing sequences can be used to processmaterials from a wide variety of different sources to extract usefulsubstances from the materials, and to provide partially degraded organicmaterial (when organic materials are employed) which functions as inputto further processing steps and/or sequences. Sonication can reduce themolecular weight and/or crystallinity of the materials, such as one ormore of any of the materials described herein, e.g., one or morecarbohydrate sources, such as cellulosic or lignocellulosic materials,or starchy materials.

In one method, a first material that includes cellulose having a firstnumber average molecular weight (M_(N1)) is dispersed in a medium, suchas water, and sonicated and/or otherwise cavitated, to provide a secondmaterial that includes cellulose having a second number averagemolecular weight (M_(N2)) lower than the first number average molecularweight. The second material (or the first and second material in certainembodiments) can be combined with a microorganism (with or withoutenzyme treatment) that can utilize the second and/or first material toproduce a fuel that is or includes hydrogen, an alcohol, an organicacid, a hydrocarbon or mixtures of any of these.

Since the second material has cellulose having a reduced molecularweight relative to the first material, and in some instances, a reducedcrystallinity as well, the second material is generally moredispersible, swellable, and/or soluble in a solution containing themicroorganism, e.g., at a concentration of greater than 106microorganisms/mL. These properties make the second material moresusceptible to chemical, enzymatic, and/or microbial attack relative tothe first material, which can greatly improve the production rate and/orproduction level of a desired product, e.g., ethanol. Sonication canalso sterilize the materials, but should not be used while themicroorganisms are supposed to be alive.

In some embodiments, the second number average molecular weight (M_(N2))is lower than the first number average molecular weight (M_(N1)) by morethan about 10 percent, e.g., 15, 20, 25, 30, 35, 40, 50 percent, 60percent, or even more than about 75 percent.

In some instances, the second material has cellulose that has ascrystallinity (C₂) that is lower than the crystallinity (C₁) of thecellulose of the first material. For example, (C₂) can be lower than(C₁) by more than about 10 percent, e.g., 15, 20, 25, 30, 35, 40, oreven more than about 50 percent.

In some embodiments, the starting crystallinity index (prior tosonication) is from about 40 to about 87.5 percent, e.g., from about 50to about 75 percent or from about 60 to about 70 percent, and thecrystallinity index after sonication is from about 10 to about 50percent, e.g., from about 15 to about 45 percent or from about 20 toabout 40 percent. However, in certain embodiments, e.g., after extensivesonication, it is possible to have a crystallinity index of lower than 5percent. In some embodiments, the material after sonication issubstantially amorphous.

In some embodiments, the starting number average molecular weight (priorto sonication) is from about 200,000 to about 3,200,000, e.g., fromabout 250,000 to about 1,000,000 or from about 250,000 to about 700,000,and the number average molecular weight after sonication is from about50,000 to about 200,000, e.g., from about 60,000 to about 150,000 orfrom about 70,000 to about 125,000. However, in some embodiments, e.g.,after extensive sonication, it is possible to have a number averagemolecular weight of less than about 10,000 or even less than about5,000.

In some embodiments, the second material can have a level of oxidation(O₂) that is higher than the level of oxidation (O₁) of the firstmaterial. A higher level of oxidation of the material can aid in itsdispersability, swellability and/or solubility, further enhancing thematerial's susceptibility to chemical, enzymatic or microbial attack. Insome embodiments, to increase the level of the oxidation of the secondmaterial relative to the first material, the sonication is performed inan oxidizing medium, producing a second material that is more oxidizedthan the first material. For example, the second material can have morehydroxyl groups, aldehyde groups, ketone groups, ester groups orcarboxylic acid groups, which can increase its hydrophilicity.

In some embodiments, the sonication medium is an aqueous medium. Ifdesired, the medium can include an oxidant, such as a peroxide (e.g.,hydrogen peroxide), a dispersing agent and/or a buffer. Examples ofdispersing agents include ionic dispersing agents, e.g., sodium laurylsulfate, and non-ionic dispersing agents, e.g., poly(ethylene glycol).

In other embodiments, the sonication medium is non-aqueous. For example,the sonication can be performed in a hydrocarbon, e.g., toluene orheptane, an ether, e.g., diethyl ether or tetrahydrofuran, or even in aliquefied gas such as argon, xenon, or nitrogen.

Without wishing to be bound by any particular theory, it is believedthat sonication breaks bonds in the carbon-containing material bycreating bubbles in the medium containing the cellulose, which grow andthen violently collapse. During the collapse of the bubble, which cantake place in less than a nanosecond, the implosive force raises thelocal temperature within the bubble to about 5100 K (even higher in someinstances; see, e.g., Suslick et al., Nature 434, 52-55) and generatespressures of from a few hundred atmospheres to over 1000 atmospheres ormore. It is believed that these high temperatures and pressures thatbreak the bonds.

In addition, without wishing to be bound by any particular theory, it isbelieved that reduced crystallinity arises, at least in part, from theextremely high cooling rates during collapse of the bubbles, which canbe greater than about 10¹¹ K/second. The high cooling rates generally donot allow the cellulose to organize and crystallize, resulting inmaterials that have reduced crystallinity. Ultrasonic systems andsonochemistry are discussed in, e.g., Olli et al., U.S. Pat. No.5,766,764; Roberts, U.S. Pat. No. 5,828,156; Mason, Chemistry withUltrasound, Elsevier, Oxford, (1990); Suslick (editor), Ultrasound: itsChemical, Physical and Biological Effects, VCH, Weinheim, (1988); Price,“Current Trends in Sonochemistry” Royal Society of Chemistry, Cambridge,(1992); Suslick et al., Ann. Rev. Mater. Sci. 29, 295, (1999); Suslicket al., Nature 353, 414 (1991); Hiller et al., Phys. Rev. Lett. 69, 1182(1992); Barber et al., Nature, 352, 414 (1991); Suslick et al., J. Am.Chem. Soc., 108, 5641 (1986); Tang et al., Chem. Comm., 2119 (2000);Wang et al., Advanced Mater., 12, 1137 (2000); Landau et al., J. ofCatalysis, 201, 22 (2001); Perkas et al., Chem. Comm., 988 (2001);Nikitenko et al., Angew. Chem. Inter. Ed. (December 2001); Shafi et al.,J. Phys. Chem. B 103, 3358 (1999); Avivi et al., J. Amer. Chem. Soc.121, 4196 (1999); and Avivi et al., J. Amer. Chem. Soc. 122, 4331(2000).

Pyrolysis

One or more pyrolysis processing sequences can be used to processcarbon-containing materials from a wide variety of different sources toextract useful substances from the materials, and to provide partiallydegraded materials which function as input to further processing stepsand/or sequences.

In one example, a first material that includes cellulose having a firstnumber average molecular weight (M_(N1)) is pyrolyzed, e.g., by heatingthe first material in a tube furnace (in the presence or absence ofoxygen), to provide a second material that includes cellulose having asecond number average molecular weight (M_(N2)) lower than the firstnumber average molecular weight. The second material (or the first andsecond material in certain embodiments) is/are combined with amicroorganism (with or without acid or enzymatic hydrolysis) that canutilize the second and/or first material to produce a fuel that is orincludes hydrogen, an alcohol (e.g., ethanol or butanol, such as n-, secor t-butanol), an organic acid, a hydrocarbon or mixtures of any ofthese.

Since the second material has cellulose having a reduced molecularweight relative to the first material, and in some instances, a reducedcrystallinity as well, the second material is generally moredispersible, swellable and/or soluble in a solution containing themicroorganism, e.g., at a concentration of greater than 10⁶microorganisms/mL. These properties make the second material moresusceptible to chemical, enzymatic and/or microbial attack relative tothe first material, which can greatly improve the production rate and/orproduction level of a desired product, e.g., ethanol. Pyrolysis can alsosterilize the first and second materials.

In some embodiments, the second number average molecular weight (M_(N2))is lower than the first number average molecular weight (M_(N1)) by morethan about 10 percent, e.g., 15, 20, 25, 30, 35, 40, 50 percent, 60percent, or even more than about 75 percent.

In some instances, the second material has cellulose that has ascrystallinity (C₂) that is lower than the crystallinity (C₁) of thecellulose of the first material. For example, (C₂) can be lower than(C₁) by more than about 10 percent, e.g., 15, 20, 25, 30, 35, 40, oreven more than about 50 percent.

In some embodiments, the starting crystallinity (prior to pyrolysis) isfrom about 40 to about 87.5 percent, e.g., from about 50 to about 75percent or from about 60 to about 70 percent, and the crystallinityindex after pyrolysis is from about 10 to about 50 percent, e.g., fromabout 15 to about 45 percent or from about 20 to about 40 percent.However, in certain embodiments, e.g., after extensive pyrolysis, it ispossible to have a crystallinity index of lower than 5 percent. In someembodiments, the material after pyrolysis is substantially amorphous.

In some embodiments, the starting number average molecular weight (priorto pyrolysis) is from about 200,000 to about 3,200,000, e.g., from about250,000 to about 1,000,000 or from about 250,000 to about 700,000, andthe number average molecular weight after pyrolysis is from about 50,000to about 200,000, e.g., from about 60,000 to about 150,000 or from about70,000 to about 125,000. However, in some embodiments, e.g., afterextensive pyrolysis, it is possible to have a number average molecularweight of less than about 10,000 or even less than about 5,000.

In some embodiments, the second material can have a level of oxidation(O₂) that is higher than the level of oxidation (O₁) of the firstmaterial. A higher level of oxidation of the material can aid in itsdispersability, swellability and/or solubility, further enhancing thematerials susceptibility to chemical, enzymatic or microbial attack. Insome embodiments, to increase the level of the oxidation of the secondmaterial relative to the first material, the pyrolysis is performed inan oxidizing environment, producing a second material that is moreoxidized than the first material. For example, the second material canhave more hydroxyl groups, aldehyde groups, ketone groups, ester groupsor carboxylic acid groups, which can increase its hydrophilicity.

In some embodiments, the pyrolysis of the materials is continuous. Inother embodiments, the material is pyrolyzed for a pre-determined time,and then allowed to cool for a second pre-determined time beforepyrolyzing again.

Oxidation

One or more oxidative processing sequences can be used to processcarbon-containing materials from a wide variety of different sources toextract useful substances from the materials, and to provide partiallydegraded and/or altered material which functions as input to furtherprocessing steps and/or sequences.

In one method, a first material that includes cellulose having a firstnumber average molecular weight (M_(N1)) and having a first oxygencontent (O₁) is oxidized, e.g., by heating the first material in astream of air or oxygen-enriched air, to provide a second material thatincludes cellulose having a second number average molecular weight(M_(N2)) and having a second oxygen content (O₂) higher than the firstoxygen content (O₁).

Such materials can also be combined with a solid and/or a liquid. Theliquid and/or solid can include a microorganism, e.g., a bacterium,and/or an enzyme. For example, the bacterium and/or enzyme can work onthe cellulosic or lignocellulosic material to produce a fuel, such asethanol, or a coproduct, such as a protein. Fuels and coproducts aredescribed in FIBROUS MATERIALS AND COMPOSITES,” U.S. Ser. No.11/453,951, filed Jun. 15, 2006. The entire contents of each of theforegoing applications are incorporated herein by reference.

In some embodiments, the second number average molecular weight is notmore 97 percent lower than the first number average molecular weight,e.g., not more than 95 percent, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45,40, 30, 20, 12.5, 10.0, 7.5, 5.0, 4.0, 3.0, 2.5, 2.0 or not more than1.0 percent lower than the first number average molecular weight. Theamount of reduction of molecular weight will depend upon theapplication. For example, in some preferred embodiments that providecomposites, the second number average molecular weight is substantiallythe same as the first number average molecular weight. In otherapplications, such as making ethanol or another fuel or coproduct, ahigher amount of molecular weight reduction is generally preferred.

In some embodiments in which the materials are used to make a fuel or acoproduct, the starting number average molecular weight (prior tooxidation) is from about 200,000 to about 3,200,000, e.g., from about250,000 to about 1,000,000 or from about 250,000 to about 700,000, andthe number average molecular weight after oxidation is from about 50,000to about 200,000, e.g., from about 60,000 to about 150,000 or from about70,000 to about 125,000. However, in some embodiments, e.g., afterextensive oxidation, it is possible to have a number average molecularweight of less than about 10,000 or even less than about 5,000.

In some embodiments, the second oxygen content is at least about fivepercent higher than the first oxygen content, e.g., 7.5 percent higher,10.0 percent higher, 12.5 percent higher, 15.0 percent higher or 17.5percent higher. In some preferred embodiments, the second oxygen contentis at least about 20.0 percent higher than the first oxygen content ofthe first material. Oxygen content is measured by elemental analysis bypyrolyzing a sample in a furnace operating at 1300° C. or higher. Asuitable elemental analyzer is the LECO CHNS-932 analyzer with a VTF-900high temperature pyrolysis furnace.

Without wishing to be bound by any particular theory, it is believedthat oxidation increases the number of hydrogen-bonding groups on thematerial, e.g., a lignocellulosic or cellulosic material. Examples ofsuch hydrogen-bonding groups include hydroxyl groups, aldehyde groups,ketone group, carboxylic acid groups or anhydride groups Such groups canincrease the material's dispersability and/or its solubility (e.g., in aliquid).

Generally, oxidation of a material occurs in an oxidizing environment.For example, the oxidation can be effected or aided by pyrolysis in anoxidizing environment, such as in air or argon enriched in air. To aidin the oxidation, various chemical agents, such as oxidants, acids orbases can be added to the material prior to or during oxidation. Forexample, a peroxide (e.g., benzoyl peroxide) can be added prior tooxidation.

Some oxidative methods of reducing recalcitrance in a carbon-containingmaterial, such as coal or cellulosic or lignocellulosic materials,employ Fenton or Fenten-type chemistry. Fenten-type chemistry isdiscussed in Pestovsky et al., Angew. Chem., Int. Ed. 2005, 44,6871-6874, the entire disclosure of which is hereby incorporated byreference herein. Generally, to utilize such methods, a first material,such as a cellulosic or lignocellulosic material, having a first levelof recalcitrance is provided and combined with one or more compoundsthat include one or more naturally-occurring, non-radioactive group 5,6, 7, 8, 9, 10 or 11 elements to provide a mixture. Optionally, one ormore oxidants capable of increasing an oxidation state of at least someof the elements are also combined with the mixture. The mixture ispermitted to contact the material and such contact is maintained for aperiod of time and under conditions sufficient to produce a secondmaterial, such as a cellulosic or lignocellulosic material, having asecond level of recalcitrance lower than the first level ofrecalcitrance.

In some embodiments, the one or more elements are in a 1+, 2+, 3+, 4+ or5+ oxidation state. In particular instances, the one or more elementsinclude Mn, Fe, Co, Ni, Cu or Zn, preferably Fe or Co. For example, theFe or Co can be in the form of a sulfate, e.g., iron(II) or iron(III)sulfate. In particular instances, the one or more elements are in a 2+,3+ or 4+ oxidation state. For example, iron can be in the form ofiron(II), iron(III) or iron(IV).

Exemplary iron (II) compounds include ferrous sulfate heptahydrate,iron(II) acetylacetonate, (+)-iron(II) L-ascorbate, iron(II) bromide,iron(II) chloride, iron(II) chloride hydrate, iron(II) chloridetetrahydrate, iron(II) ethylenediammonium sulfate tetrahydrate, iron(II)fluoride, iron(II) gluconate hydrate, iron(II) D-gluconate dehydrate,iron(II) iodide, iron(II) lactate hydrate, iron(II) molybdate, iron(II)oxalate dehydrate, iron(II) oxide, iron(II,III) oxide, iron(II)perchlorate hydrate, iron(II) phthalocyanine, iron(II) phthalocyaninebis(pyridine) complex, iron(II) sulfate heptahydrate, iron(II) sulfatehydrate, iron(II) sulfide, iron(II) tetrafluoroborate hexahydrate,iron(II) titanate, ammonium iron(II) sulfate hexahydrate, ammoniumiron(II) sulfate, cyclopentadienyl iron(II) dicarbonyl dimmer,ethylenediaminetetraacetic acid hydrate iron(III) sodium salt and ferriccitrate.

Exemplary iron (III) compounds include iron(III) acetylacetonate,iron(III) bromide, iron(III) chloride, iron(III) chloride hexahydrate,iron(III) chloride solution, iron(III) chloride on silica gel, iron(III)citrate, tribasic monohydrate, iron(III) ferrocyanide, iron(III)fluoride, iron(III) fluoride trihydrate, iron(III) nitrate nonahydrate,iron(III) nitrate on silica gel, iron(III) oxalate hexahydrate,iron(III) oxide, iron(III) perchlorate hydrate, iron(III) phosphate,iron(III) phosphate dehydrate, iron(III) phosphate hydrate, iron(III)phosphate tetrahydrate, iron(III) phthalocyanine chloride, iron(III)phthalocyanine-4,4′,4″,4″′-tetrasulfonic acid, compound with oxygenhydrate monosodium salt, iron(III) pyrophosphate, iron(III) sulfatehydrate, iron(III) p-toluenesulfonate hexahydrate, iron(III)tris(2,2,6,6-tetramethyl-3,5-heptanedionate) and ammonium iron(III)citrate.

Exemplary cobalt (II) compounds include cobalt(II) acetate, cobalt(II)acetate tetrahydrate, cobalt(II) acetylacetonate hydrate, cobalt(II)benzoylacetonate, cobalt(II) bromide, cobalt(II) bromide hydrate andcobalt(II) carbonate hydrate.

Exemplary cobalt (III) compounds include cobalt(III) acetylacetonate,cobalt(III) fluoride, cobalt(III) oxide, cobalt(III) sepulchratetrichloride, hexammine cobalt(III) chloride,bis(cyclopentadienyl)cobalt(III) hexafluorophosphate andbis(ethylcyclopentadienyl)cobalt(III) hexafluorophosphate.

Exemplary oxidants include peroxides, such as hydrogen peroxide andbenzoyl peroxide, persulfates, such as ammonium persulfate, activatedforms of oxygen, such as ozone, permanganates, such as potassiumpermanganate, perchlorates, such as sodium perchlorate, andhypochlorites, such as sodium hypochlorite (household bleach).

In some situations, pH is maintained at or below about 5.5 duringcontact, such as between 1 and 5, between 2 and 5, between 2.5 and 5 orbetween about 3 and 5. Conditions can also include a contact period ofbetween 2 and 12 hours, e.g., between 4 and 10 hours or between 5 and 8hours. In some instances, conditions include not exceeding 300° C.,e.g., not exceeding 250, 200, 150, 100 or 50° C. In special desirableinstances, the temperature remains substantially ambient, e.g., at orabout 20-25° C.

In some desirable embodiments, the one or more oxidants are applied to afirst cellulosic or lignocellulosic material and the one or morecompounds as a gas, such as by generating ozone in-situ by irradiatingthe first cellulosic or lignocellulosic material and the one or morecompounds through air with a beam of particles, such as electrons.

In particular desirable embodiments, a first cellulosic orlignocellulosic material is firstly dispersed in water or an aqueousmedium that includes the one or more compounds dispersed and/ordissolved therein, water is removed after a soak time (e.g., loose andfree water is removed by filtration), and then the one or more oxidantsare applied to the combination as a gas, such as by generating ozonein-situ by irradiating the first cellulosic or lignocellulosic and theone or more compounds through air with a beam of particles, such aselectrons (e.g., each being accelerated by a potential difference ofbetween 3 MeV and 10 MeV). Soaking can open up interior portions tooxidation.

In some embodiments, the mixture includes one or more compounds and oneor more oxidants, and a mole ratio of the one or more compounds to theone or more oxidants is from about 1:1000 to about 1:25, such as fromabout 1:500 to about 1:25 or from about 1:100 to about 1:25.

In some desirable embodiments, the mixture further includes one or morehydroquinones, such as 2,5-dimethoxyhydroquinone (DMHQ) and/or one ormore benzoquinones, such as 2,5-dimethoxy-1,4-benzoquinone (DMBQ), whichcan aid in electron transfer reactions.

In some desirable embodiments, the one or more oxidants areelectrochemically-generated in-situ. For example, hydrogen peroxideand/or ozone can be electro-chemically produced within a contact orreaction vessel.

Other Processes to Solubilize, Reduce Recalcitrance or to Functionalize

Any of the processes of this paragraph can be used alone without any ofthe processes described herein, or in combination with any of theprocesses described herein (in any order): steam explosion, acidtreatment (including concentrated and dilute acid treatment with mineralacids, such as sulfuric acid, hydrochloric acid and organic acids, suchas trifluoroacetic acid), base treatment (e.g., treatment with lime orsodium hydroxide), UV treatment, screw extrusion treatment (see, e.g.,U.S. Patent Application Ser. No. 61/073,530, filed Nov. 18, 2008,solvent treatment (e.g., treatment with ionic liquids) and freezemilling (see, e.g., U.S. Patent Application Ser. No. 61/081,709).

Thermochemical Conversion

A thermochemical conversion process includes changing molecularstructures of carbon-containing material at elevated temperatures.Specific examples include gasification, pyrolysis, reformation, partialoxidation and mixtures of these (in any order).

Gasification converts carbon-containing materials into a synthesis gas(syngas), which can include methanol, carbon monoxide, carbon dioxideand hydrogen. Many microorganisms, such as acetogens or homoacetogensare capable of utilizing a syngas from the thermochemical conversion ofcoal or biomass, to produce a product that includes an alcohol, acarboxylic acid, a salt of a carboxylic acid, a carboxylic acid ester ora mixture of any of these. Gasification of carbonaceous materials, suchas coal and biomass (e.g., cellulosic or lignocellulosic materials), canbe accomplished by a variety of techniques. For example, gasificationcan be accomplished utilizing staged steam reformation with afluidized-bed reactor in which the carbonaceous material is firstpyrolyzed in the absence of oxygen and then the pyrolysis vapors arereformed to synthesis gas with steam providing added hydrogen andoxygen. In such a technique, process heat comes from burning char.Another technique utilizes a screw auger reactor in which moisture (andoxygen) are introduced at the pyrolysis stage and the process heat isgenerated from burning some of the gas produced in the latter stage.Another technique utilizes entrained flow reformation in which bothexternal steam and air are introduced in a single-stage gasificationreactor. In partial oxidation gasification, pure oxygen is utilized withno steam.

Production of Fuels Acids, Esters and/or Other Products

A typical biomass resource contains cellulose, hemicellulose, and ligninplus lesser amounts of proteins, extractables and minerals. As describedherein, the complex carbohydrates contained in the cellulose andhemicellulose fractions can be processed into fermentable sugars usingthe treatment processes described herein, optionally, along with acid orenzymatic hydrolysis. Also as discussed herein, the sugars liberated canbe converted into a variety of products, such as alcohols or organicacids. The product obtained depends upon the microorganism utilized andthe conditions under which the bioprocessing occurs.

For example, when a homoacetogen is used to convert glucose intoacetate, acetic acid or mixtures thereof (represented by the equationdirectly below),

C₆H₁₂O₆→3CH₃COOH

the reaction has nearly a 100% carbon yield and the resulting acetatecontains about 94% of the chemical energy of the initial glucose(ignoring cell mass production). Chemical energy efficiency is definedas the ratio of the heat of combustion of the products divided by theheat of combustion of the feeds, times 100 to convert into a percentage.For example, taking values from Table 3.7 of Roels, J. A., Energeticsand Kinetics in Biotechnology, Elsevier Biomedical, 1983, the heat ofcombustion (HHV basis) of glucose and acetic acid are 2807 KJ/mol and876 kJ/mol, respectively, so the chemical energy efficiency for thisreaction is (3×876/2807)×100=93.4%.

Many bacteria, such as anaerobic bacteria, are capable of fermentingsyngas components (CO, H₂, CO₂) into useful products. Table 1 shows thatmany homoacetogens will produce acetate from syngas mixtures at about77% chemical efficiency. Another class of bacteria, known asheteroacetogens, can produce ethanol directly from syngas mixtures atchemical energy efficiencies of about 80%. The literature has many moreexamples of bacteria, such as anaerobic bacteria, capable ofmetabolizing both sugar and syngas feedstocks. For example, theAcetonema and Eubacterium (Butyribacterium) can produce mixtures ofacetate and butyric acids from many of the materials described herein.

TABLE 1 Examples of chemical energy efficiencies of homoacetogens andhetroacetogens Chemical Energy Efficiency, % Homoacetogens 4CO +2H₂O→CH₃COOH + 2CO₂ 77.4 2CO + 2H₂→CH₃COOH 77.0 2CO₂ + 4H₂→CH₃COOH +2H₂O 76.6 Heteroacetogens - Ethanol as Major Product 6CO +3H₂O→CH₃CH₂OH + 4CO₂ 80.6 2CO + 4H₂→CH₃CH₂OH + H₂O 80.1 2CO₂ +6H₂→CH₃CH₂OH + 3H₂O 79.8 (computations based on values in Roels, J. A.,Energetics and Kinetics in Biotechnology, Elsevier Biomedical, 1983)

Typical exemplary products from such homoacetogen or heteroacetogenconversion (e.g., fermentation) include acetate, propionate, butyrate,hydrogen, carbon dioxide, and methane. A pure culture of one or morehomoacetogens can be used to drive most of the products to acetate. Thisacetate can then be recovered as an organic salt or organic acid, orfurther transformed into an aldehyde, ester, alcohol or alkene. Theresulting organic acid mixture can be recovered and/or transformed intoorganic acid salts, acids, aldehydes, esters, alcohols, alkenes. Ifdesired, the mixtures can be separated into relatively pure fractions.

Both sugar and syngas pathways in acetogens and other bacteria can beutilized to drive the carbon and chemical energy of any feedstockmaterial described herein into acetate or any other product or coproductdescribed herein (actual products and coproducts depending uponmicroorganism and conditions utilized). One advantage of utilizing bothsugars and syngas for conversion is that this removes any restrictionson the maximum obtainable energy efficiency caused by limitations in theamount of carbon present in the feedstock material in the form offermentable and/or complex carbohydrates. This is especially useful forbiomass feedstock materials with relatively low levels of energy in theform of carbohydrates, such as high lignin lignocellulosic material.

Generally, various microorganisms can produce a number of usefulproducts, such as a fuel, by operating on, e.g., fermenting the treatedcarbon-containing materials.

The microorganism can be a natural microorganism or an engineeredmicroorganism. For example, the microorganism can be a bacterium, e.g.,a cellulolytic bacterium, a fungus, e.g., a yeast, a plant or a protist,e.g., an algae, a protozoa or a fungus-like protist, e.g., a slime mold.When the organisms are compatible, mixtures of organisms can beutilized. The microorganism can be an aerobe or an anaerobe. Themicroorganism can be a homofermentative microorganism (produces a singleor a substantially single end product). The microorganism can be ahomoacetogenic microorganism, a homolactic microorganism, a propionicacid bacterium, a butyric acid bacterium, a succinic acid bacterium or a3-hydroxypropionic acid bacterium. The microorganism can be of a genusselected from the group Clostridium, Lactobacillus, Moorella,Thermoanaerobacter, Proprionibacterium, Propionispera,Anaerobiospirillum, and Bacteriodes. In specific instances, themicroorganism can be Clostridium formicoaceticum, Clostridium butyricum,Moorella thermoacetica, Thermoanaerobacter kivui, Lactobacillusdelbrukii, Propionibacterium acidipropionici, Propionispera arboris,Anaerobiospirillum succinicproducens, Bacteriodes amylophilus orBacteriodes ruminicola. For example, the microorganism can be arecombinant microorganism engineered to produce a desired product, suchas a recombinant Escherichia coli transformed with one or more genescapable of encoding proteins that direct the production of the desiredproduct is used (see, e.g., U.S. Pat. No. 6,852,517, issued Feb. 8,2005).

Other microorganisms include strains of the genus Sacchromyces spp.e.g., Sacchromyces cerevisiae (baker's yeast), Saccharomyces distaticus,Saccharomyces uvarum; the genus Kluyveromyces, e.g., speciesKluyveromyces marxianus, Kluyveromyces fragilis; the genus Candida,e.g., Candida pseudotropicalis, and Candida brassicae, the genusClavispora, e.g., species Clavispora lusitaniae and Clavispora opuntiaethe genus Pachysolen, e.g., species Pachysolen tannophilus, the genusBretannomyces, e.g., species Bretannomyces clausenii (Philippidis, G.P., 1996, Cellulose bioconversion technology, in Handbook on Bioethanol:Production and Utilization, Wyman, C. E., ed., Taylor & Francis,Washington, D.C., 179-212).

Commercially available yeasts include, for example, Red Star®/LesaffreEthanol Red (available from Red Star/Lesaffre, USA) FALI® (availablefrom Fleischmann's Yeast, a division of Burns Philip Food Inc., USA),SUPERSTART® (available from Alltech), GERT STRAND® (available from GertStrand AB, Sweden) and FERMOL® (available from DSM Specialties).

Bacteria that can ferment bimoss to ethanol and other products include,e.g., Zymomonas mobilis and Clostridium thermocellum (Philippidis, 1996,supra). Leschine et al. (International Journal of Systematic andEvolutionary Microbiology 2002, 52, 1155-1160) isolated an anaerobic,mesophilic, cellulolytic bacterium from forest soil, Clostridiumphytofermentans sp. nov., which converts cellulose to ethanol.

Fermentation of biomass to ethanol and other products may be carried outusing certain types of thermophilic or genetically engineeredmicroorganisms, such Thermoanaerobacter species, including T. mathranii,and yeast species such as Pichia species. An example of a strain of T.mathranii is A3M4 described in Sonne-Hansen et al. (Applied Microbiologyand Biotechnology 1993, 38, 537-541) or Ahring et al. (Arch. Microbiol.1997, 168, 114-119).

To aid in the breakdown of the materials that include the cellulose(treated by any method described herein or even untreated), one or moreenzymes, e.g., a cellulolytic enzyme can be utilized. In someembodiments, the materials that include the cellulose are first treatedwith the enzyme, e.g., by combining the material and the enzyme in anaqueous solution. This material can then be combined with anymicroorganism described herein. In other embodiments, the materials thatinclude the cellulose, the one or more enzymes and the microorganism arecombined concurrently, e.g., by combining in an aqueous solution.

Enzymes and biomass-destroying organisms that break down biomass, suchas the cellulose and/or the lignin portions of the biomass, contain ormanufacture various cellulolytic enzymes (cellulases), ligninases orvarious small molecule biomass-destroying metabolites. These enzymes maybe a complex of enzymes that act synergistically to degrade crystallinecellulose or the lignin portions of biomass. Examples of cellulolyticenzymes include: endoglucanases, cellobiohydrolases, and cellobiases(β-glucosidases). A cellulosic substrate is initially hydrolyzed byendoglucanases at random locations producing oligomeric intermediates.These intermediates are then substrates for exo-splitting glucanasessuch as cellobiohydrolase to produce cellobiose from the ends of thecellulose polymer. Cellobiose is a water-soluble 1,4-linked dimer ofglucose. Finally cellobiase cleaves cellobiose to yield glucose.

A cellulase is capable of degrading biomass and may be of fungal orbacterial origin. Suitable enzymes include cellulases from the generaBacillus, Pseudomonas, Humicola, Fusarium, Thielavia, Acremonium,Chrysosporium and Trichoderma, and include species of Humicola,Coprinus, Thielavia, Fusarium, Myceliophthora, Acremonium,Cephalosporium, Scytalidium, Penicillium or Aspergillus (see, e.g., EP458162), especially those produced by a strain selected from the speciesHumicola insolens (reclassified as Scytalidium thermophilum, see, e.g.,U.S. Pat. No. 4,435,307), Coprinus cinereus, Fusarium oxysporum,Myceliophthora thermophila, Meripilus giganteus, Thielavia terrestris,Acremonium sp., Acremonium persicinum, Acremonium acremonium, Acremoniumbrachypenium, Acremonium dichromosporum, Acremonium obclavatum,Acremonium pinkertoniae, Acremonium roseogriseum, Acremoniumincoloratum, and Acremonium furatum; preferably from the speciesHumicola insolens DSM 1800, Fusarium oxysporum DSM 2672, Myceliophthorathermophila CBS117.65, Cephalosporium sp. RYM-202, Acremonium sp. CBS478.94, Acremonium sp. CBS 265.95, Acremonium persicinum CBS169.65,Acremonium acremonium AHU 9519, Cephalosporium sp. CBS 535.71,Acremonium brachypenium CBS 866.73, Acremonium dichromosporum CBS683.73, Acremonium obclavatum CBS 311.74, Acremonium pinkertoniaeCBS157.70, Acremonium roseogriseum CBS134.56, Acremonium incoloratumCBS146.62, and Acremonium furatum CBS 299.70H. Cellulolytic enzymes mayalso be obtained from Chrysosporium, preferably a strain ofChrysosporium lucknowense. Additionally, Trichoderma (particularlyTrichoderma viride, Trichoderma reesei, and Trichoderma koningii),alkalophilic Bacillus (see, for example, U.S. Pat. No. 3,844,890 and EP458162), and Streptomyces (see, e.g., EP 458162) may be used.

Other methods utilize one or more ligninases and/or biomass-destroyingenzymes to reduce recalcitrance in cellulosic or lignocellulosicmaterials. In such methods, a first cellulosic or lignocellulosicmaterial having a first level of recalcitrance is provided and combinedwith one or more ligninases and/or one or more biomass-destroying, e.g.,lignin-destroying organisms, so as to contact the first cellulosic orlignocellulosic material. The contact is maintained for a period oftime, such as between 2 and 24 hours, e.g., between 6 and 12 hours, andunder conditions sufficient, e.g., below a pH of about 6, such asbetween pH 3 and 5.5, to produce a second lignocellulosic materialhaving a second level of recalcitrance lower than the first level ofrecalcitrance. After reduction of the recalcitrance, the secondcellulosic or lignocellulosic material can be contacted with one or moreenzymes and/or microorganisms, e.g., to make any product describedherein, e.g., food or fuel, e.g., ethanol or butanol (e.g., n-butanol)or any product described in any application incorporated by referenceherein.

The ligninase can be, e.g., one or more of manganese peroxidase, ligninperoxidase or laccases.

In particular implementations, the biomass-destroying organism can be,e.g., one or more of white rot, brown rot or soft rot. For example, thebiomass-destroying organism can be a Basidiomycetes fungus. Inparticular embodiments, the biomass-destroying organism is Phanerochaetechrysoporium or Gleophyllum trabeum.

Ligninases, biomass-destroying organisms and small molecule metabolitesare described in Kirk et al., Enzyme Microb. Technol. 1986, vol. 8,27-32, Kirk et al., Enzymes for Pulp and Paper Processing, Chapter 1(Roles for Microbial Enzymes in Pulp and Paper Processing and Kirk etal., The Chemistry of Solid Wood, Chapter 12 (Biological Decompositionof Solid Wood (pp. 455-487).

Referring now to FIG. 2, one method of producing ethanol from a materialthat includes carbon-containing compounds, such as a lignocellulosicmaterial treated with accelerated electrons in which less than about 75%by weight of the carbon-containing compounds are in the form ofcarbohydrates, includes biologically converting (with or withoutenzymatic assistance) a portion of the material into acetic acid, anacetate ester (e.g., a methyl or ethyl ester), an acetate salt, or amixture of acetic acid, acetate ester and acetate salt (shown as simplyCH₃COOH and CH₃COOR in the figure) and converting another portion of thematerial using a thermochemical process (gasification) to produce asyngas (a mixture of hydrogen, carbon monoxide, and in some instances,carbon dioxide or a component thereof (often referred to as a reducinggas)—shown in the figure as H₂). The syngas or a component thereof isthen reacted with the acetic acid, acetate ester, acetate salt, or amixture of acetic acid, acetate ester and acetate salt, e.g., in thepresence of a catalyst and under a high pressure of hydrogen (e.g., 50bar to 700 bar) to produce ethanol. The chemical energy efficiency ofthis method to produce ethanol can be greater than the chemical energyefficiency of either a solely biological conversion process or aconversion process in which all of the material is initially subjectedto a thermochemical conversion step as part of the process to produceethanol.

In some instances, acid and/or acid salt is (are) the product(s)produced by the biological process. In such instances, the acid and/oracid salt can be treated by acidification and/or esterification prior tothe step of reacting with a thermochemical process-producedintermediate. For example, an intermediate produced by the biologicalprocess can include a salt of a carboxylic acid, which can be acidifiedto the carboxylic acid. For example, the biological process-producedintermediate can include a carboxylic acid that can be esterified, withmethanol or ethanol to form the corresponding carboxylic acid esters.Acidification and esterification can be accomplished by biological orchemical means. For example, in one embodiment, acidifying can includeintroducing carbon dioxide or an acid with a lower pKa than thecarboxylic acid being acidified to a solution that includes the salt ofthe carboxylic acid. In another embodiment, acidifying can includeintroducing a tertiary amine with carbon dioxide to form an acid/aminecomplex. This process can further include contacting the acid/aminecomplex with a water immiscible solvent to form an ester of the waterimmiscible solvent and the carboxylic acid. Methods of acidification andesterification are described in more detail in WO 2005/073161 publishedon Aug. 11, 2005 and in WO 00/53791 published on Sep. 14, 2000.

Referring to FIG. 3, another method of producing ethanol from a materialthat includes carbon-containing compounds, such as a lignocellulosicmaterial treated with ozone or Fenton's solution, includes biologicallyconverting (without or without enzymatic assistance) a portion of thematerial into acetic acid, an acetate ester, an acetate salt, or amixture of acetic acid, acetate ester and acetate salt (shown as simplyCH₃COOH and CH₃COOR in the figure) and converting another portion of thematerial using a thermochemical process (gasification) to produce asyngas. A portion of the syngas in the form of carbon monoxide andhydrogen is fed into the biological process during conversion. Anotherportion of the syngas (hydrogen) is utilized to react with the aceticacid, acetate ester, acetate salt, or a mixture of acetic acid, acetateester and acetate salt, e.g., in the presence of a catalyst and under ahigh pressure of hydrogen (e.g., 25 or 50 bar to 700 bar) to produceethanol.

Referring to FIG. 4, another method of producing ethanol from a materialthat includes carbon-containing compounds, such as a lignocellulosicmaterial sonicated to reduce its recalcitrance, includes biologicallyconverting (without or without enzymes being present) a portion of thematerial into acetic acid, an acetate ester, an acetate salt, or amixture of acetic acid, acetate ester and acetate salt (shown as simplyCH₃COOH and CH₃COOR in the figure) and converting another portion of thematerial using a thermochemical process (gasification) to produce asyngas. A portion of the syngas in the form of carbon monoxide is fedinto the biological conversion process. Another portion of the syngas inthe form of hydrogen is utilized to react with the acetic acid, acetateester, acetate salt, or a mixture of acetic acid, acetate ester andacetate salt to produce ethanol.

Referring to FIG. 5, another method of producing ethanol from a materialthat includes carbon-containing compounds, such as a lignocellulosicmaterial pyrolyzed to reduce its recalcitrance, includes biologicallyconverting (without or without enzymes being present) a portion of thematerial into acetic acid, an acetate ester, an acetate salt, or amixture of acetic acid, acetate ester and acetate salt (shown as simplyCH₃COOH and CH₃COOR in the figure) and converting another portion of thematerial using a thermochemical process (gasification) to produce asyngas. A portion of the syngas in the form of carbon monoxide andhydrogen is fed into the biological conversion process. Another portionof the syngas in the form of carbon monoxide is utilized to react withthe acetic acid, acetate ester, acetate salt, or a mixture of aceticacid, acetate ester and acetate salt to produce ethanol.

Referring to FIG. 6, another method of producing ethanol from a materialthat includes carbon-containing compounds, such as coal pyrolyzed toreduce its recalcitrance, includes biologically converting (without orwithout enzymes being present) a portion of the material into aceticacid, an acetate ester, an acetate salt, or a mixture of acetic acid,acetate ester and acetate salt (shown as simply CH₃COOH and CH₃COOR inthe figure) and converting another portion of the material using athermochemical process (gasification) to produce a syngas that includeshydrogen and methanol. A portion of the syngas in the form of methanol(CH₃OH) is fed into the biological conversion process. Another portionof the syngas in the form of hydrogen is utilized to react with theacetic acid, acetate ester, acetate salt, or a mixture of acetic acid,acetate ester and acetate salt to produce ethanol.

Referring to FIG. 7, another method of producing ethanol from a materialthat includes carbon-containing compounds, such as a lignocellulosicmaterial treated with ozone or Fenton's solution and/or irradiated withelectrons, includes biologically converting (without or without enzymesbeing present) the entire portion of the material that is biologicallyconvertible into acetic acid, an acetate ester, an acetate salt, or amixture of acetic acid, acetate ester and acetate salt (shown as simplyCH₃COOH and CH₃COOR in the figure). The conversion residue, e.g., thelignin portion of the lignocellulosic material, is then converted usinga thermochemical process (e.g., gasification) to produce a syngas. Aportion of the syngas in the form of hydrogen is utilized to react withthe acetic acid, acetate ester, acetate salt, or a mixture of aceticacid, acetate ester and acetate salt, e.g., in the presence of acatalyst and under a high pressure of hydrogen (e.g., 25 or 50 bar to700 bar) to produce ethanol.

In some instances, acetate salts are selectively produced, which can beconverted to esters (e.g., ethyl esters) using a reactive distillationprocess 80 a that is shown in FIG. 7A.

In the reaction section 424, a dilute (5%) solution of calcium acetatein water is mixed with ethanol and fed to the column 422 at the top ofthe reaction section. Carbon dioxide is fed to the column 422 at thebottom of the reaction section 424. The simultaneous reaction of carbondioxide with calcium acetate and ethanol takes place in the reactionzone 424 in the center section of the column 422 with the formation ofcalcium carbonate and ethyl acetate (EtAc).

The most volatile component in the reaction mixture is the ethylacetate/water/ethanol azeotrope. The azeotrope composition is 82.6%ethyl acetate, 9% water and 8.4% ethanol and has a normal boiling pointof 70.2° C. The azeotrope is removed from the reaction mixture byvaporization along with some EtOH and water. The bottom product from thereaction zone is a water and ethanol solution containing the suspendedcalcium carbonate, which flows to the stripping section.

In the upper separation section 450, the azeotrope is separated from theethanol and water also vaporized from the reaction mixture. Theethanol/water mixture is recycled to the reaction zone 424 and theoverhead product is the azeotrope. The carbon dixoxide is separated fromthe overhead condensate and recycled to the column with makeup carbondioxide. The azeotrope can be broken by the addition of water, whichcauses a phase separation, with the water and ethanol rich phase beingreturned to the appropriate point in the reactive distillation column.

Since excess ethanol is used to favor the forward esterificationreaction in the reaction section, the stripping section 458 returns theexcess ethanol to the reaction zone. In the stripping section 458, theethanol is removed from the calcium carbonate-containing water stream,which is discharged from the column 422 and separated by a liquid/solidseparation 462, such as centrifugation or filtration.

The net effect of the reactive distillation process is to recover theacetic acid from the dilute salt solution, thereby producing arelatively concentrated product stream at the top and without vaporizingthe water that forms the bulk of the stream. The integration of thethree sections reduces the overall energy requirements and thesimultaneous removal of the product ester shifts the esterificationequilibrium, which gives a higher conversion in a shorter time.

Referring now to FIG. 8, one method of producing propylene glycol(propane-1,2-diol) from a material that includes carbon-containingcompounds, such as a lignocellulosic material treated with acceleratedelectrons in which less than about 75% by weight of thecarbon-containing compounds are in the form of carbohydrates, includesbiologically converting (without or without enzymatic assistance) aportion of the material into lactic acid, a lactate ester, a lactatesalt, or mixtures thereof (shown as simply CH₃CH(OH)COOH andCH₃CH(OH)COOR in the figure) and converting another portion of thematerial using a thermochemical process (e.g., gasification) to producea syngas (shown in the figure as H₂). The syngas is then reacted withthe lactic acid, a lactate ester, a lactate salt, or mixtures thereof,e.g., in the presence of a catalyst and under a high pressure ofhydrogen (e.g., 25 or 50 bar to 700 bar) to produce propylene glycol.

Utilizing processes analogous to those discussed herein,carbon-containing materials can be utilized to produce n-propanol, e.g.,from a mixture that includes propionic acid, a propionate ester, apropionate salt, acetic acid, an acetate ester, an acetate salt or amixture thereof.

Utilizing processes analogous to those discussed herein,carbon-containing materials can be utilized to produce butanol andethanol, e.g., from a mixture that includes butyric acid, a butyrateester, a butyrate salt, acetic acid, an acetate ester, an acetate saltor a mixture of butyric acid, butyrate ester, butyrate salt, aceticacid, acetate ester and acetate salt.

Utilizing processes analogous to those discussed herein,carbon-containing materials can be utilized to produce 1,4-butanediol,e.g., from a mixture that includes succinic acid, a succinate ester, asuccinate salt, or a mixture of succinic acid, succinate ester andsuccinate salt.

Utilizing processes analogous to those discussed herein,carbon-containing materials can be utilized to produce1,3-propanediol,e.g., from a mixture that includes 3-hydroxypropionic acid,3-hydroxypropionate ester, 3-hydroxypropionate salt, or a mixture of3-hydroxypropionic acid, 3-hydroxypropionate ester and3-hydroxypropionate salt.

Other Embodiments

A number of embodiments have been described. Nevertheless, it will beunderstood that various modifications may be made without departing fromthe spirit and scope of the disclosure.

For example, while syngas and syngas components can be produced on-sitefrom a carbon-containing material feedstock, the syngas or any componentthereof can also be purchased, e.g., from an oil refinery.

While it is possible to perform all the processes described herein allat one physical location, in some embodiments, the processes arecompleted at multiple sites. For example, the ester mixtures can betransported to a high-pressure hydrocracker at another physicallocation.

While the techniques presented herein work with carbon-containingbiomass materials, they also work with any of the othercarbon-containing materials described herein, such as coal, sugar andstarch. For example, coal or starch can be irradiated and then convertedinto organic acids, salts or acids and/or esters of organic acids.

Any carbon dioxide generated and/or lignin liberated in any processdescribed herein can be captured. Any captured carbon dioxide can besequestered, e.g., by injecting the captured carbon dioxide into ageological formation, such as an unmineable coal seam or a deep salineaquifer capable of maintaining the carbon dioxide, e.g., for a period oftime greater than 100 years, e.g., greater than 250 years, 500 years,1,000 years or greater than 10,000 years. For example, any carbondioxide produced in any process described herein can be sequestered,e.g., by fixing carbon dioxide utilizing any microorganism describedherein. For example, the microorganism can include algae and the carbondioxide can be sequestered in the form of a carbohydrate and/or lipid.If desired, e.g., to produce a bio-diesel, the lipid can be convertedinto an ester, e.g., a methyl, ethyl, n-propyl, isopropyl or butylester. Any ester can be converted to alcohol, e.g., by hydrogenating, asdescribed herein.

Referring now to FIG. 9, carbon dioxide emissions can be stored invarious geological formations. For example, the carbon dioxide can bestored in a deep saline aquifer or in an unmineable coal seam. Thecarbon dioxide can also be used to expel from the earth hard to get atnatural gas or oil.

Carbon dioxide can also be captured and used in the food and beverageindustry. For example, the carbon dioxide can be converted into dry ice,or it can be utilized in carbonated beverages.

Referring to FIG. 10, any microorganism described herein that is capableof fixing carbon dioxide can be utilized in sequestering carbon dioxide.In particular, FIG. 10 illustrates a photosynthetic pathway in whichcarbon dioxide in the presence of light, water, nutrients and amicroorganism capable of fixing carbon dioxide is converted into variousproducts, including carbohydrates and lipids. The carbohydratesgenerated can be utilized in any process described herein, such as forthe making ethanol, and the lipids can be, e.g., converted intobio-diesel, used in food or as dietary supplements.

Suitable algae include microalgae, such as diatoms and cyanobacteria,and macroalgae, e.g., seaweed. Specific examples include Botryococcusbraunii, Chlorella, Dunaliella tertiolecta, Gracilaria, Pleurochrysiscarterae (also called CCMP647), and Sargassum.

Referring now to FIG. 11, a lipid, such as a triglyceride (fat), can beconverted to bio-diesel by esterification using an alcohol (ROH) and acatalyst, such as an acid, such as a mineral acid (e.g., sulfuric acid).As shown, for each molecule of triglyceride, three molecules ofbio-diesel are formed, along with one molecule of glycerol.

Referring now to FIGS. 12 and 12 A, waste carbon dioxide and nutrientscan be fed to a circulating reaction vessel that contains algaesuspended in a solvent, such as water. A light source, such as the sunor an artificial light source shines on the materials in the reactionvessel as the paddle wheel continuously circulates the materials. Aftera desired amount of product, such as one or more carbohydrates and/orone or more lipids is produced, the contents of the reactor are emptiedand the oil is recovered and converted into a desired fuel, such as adiesel.

Lignin liberated in any process described herein can be captured andutilized. For example, the lignin can be used as captured as a plastic,or it can be synthetically upgraded to other plastics. In someinstances, it can be utilized as an energy source, e.g., burned toprovide heat. In some instances, it can also be converted tolignosulfonates, which can be utilized as binders, dispersants,emulsifiers or as sequestrants.

When used as a binder, the lignin or a lignosulfonate can, e.g., beutilized in coal briquettes, in ceramics, for binding carbon black, forbinding fertilizers and herbicides, as a dust suppressant, in the makingof plywood and particle board, for binding animal feeds, as a binder forfiberglass, as a binder in linoleum paste and as a soil stabilizer.

As a dispersant, the lignin or lignosulfonates can be used, e.g.,concrete mixes, clay and ceramics, dyes and pigments, leather tanningand in gypsum board.

As an emulsifier, the lignin or lignosulfonates can be used, e.g., inasphalt, pigments and dyes, pesticides and wax emulsions.

As a sequestrant, the lignin or lignosulfonates can be used, e.g., inmico-nutrient systems, cleaning compounds, and water treatment systems,e.g., for boiler and cooling systems.

As a heating source, lignin generally has a higher energy content thanholocellulose (cellulose and hemicellulose) since it contains morecarbon than holocellulose. For example, dry lignin can have an energycontent of between about 11,000 and 12,500 BTU per pound, compared to7,000 an 8,000 BTU per pound of holocellulose. As such, lignin can bedensified and converted into briquettes and pellets for burning. Forexample, the lignin can be converted into pellets by any methoddescribed herein. For a slower burning pellet or briquette, the lignincan be crosslinked, such as applying a radiation dose of between about0.5 Mrad and 5 Mrad. Crosslinking can make a slower burning form factor.The form factor, such as a pellet or briquette, can be converted to a“synthetic coal” or charcoal by pyrolyzing in the absence of air, e.g.,at between 400 and 950° C. Prior to pyrolyzing, it can be desirable tocrosslink the lignin to maintain structural integrity.

Accordingly, other embodiments are within the scope of the followingclaims.

1. A method of making an alcohol, a carboxylic acid, a salt of acarboxylic acid, an ester of a carboxylic acid, or a mixture of any ofthese, the method comprising: treating a carbon-containing material withone or more of radiation, sonication, pyrolysis, oxidation and steamexplosion; and converting at least a portion of the treatedcarbon-containing material utilizing a microorganism to produce aproduct comprising one or more of an alcohol, a carboxylic acid, a saltof a carboxylic acid, a carboxylic acid ester or a mixture of any ofthese.
 2. The method of claim 1, wherein during converting a syngas isdelivered to the microorganism.
 3. The method of claim 2, wherein thesyngas is selected from the group consisting of methanol, hydrogen,carbon monoxide, carbon dioxide and mixtures thereof.
 4. The method ofclaim 2, wherein the syngas comprises methanol.
 5. The method of claim2, wherein the syngas comprises carbon monoxide.
 6. The method of claim2, wherein the syngas comprises a mixture of carbon monoxide andhydrogen.
 7. The method of claim 2, wherein the syngas is produced bygasifying coal and/or a biomass.
 8. The method of claim 1, wherein themethod further comprises hydrogenating the product or exposing theproduct to one or other reducing agents, such as carbon monoxide.
 9. Themethod of claim 8, wherein hydrogenating the product comprises exposingthe product to hydrogen under a pressure of greater than about 25 bar inthe presence of a catalyst.
 10. The method of claim 9, wherein thehydrogen is produced from syngas produced by gasifying coal and/orbiomass.
 11. The method of claim 1, wherein the converting comprisescontacting the treated material with an enzyme.
 12. A method of makingan alcohol, the method comprising: treating a carbon-containing materialwith one or more of radiation, sonication, pyrolysis, oxidation andsteam explosion; converting at least a portion of the treatedcarbon-containing material utilizing a microorganism to a productcomprising a carboxylic acid, a salt of a carboxylic acid, a carboxylicacid ester or a mixture of any of these; and hydrogenating the productto produce an alcohol.
 13. The method of claim 12, wherein thecarboxylic acid comprises acetic acid.
 14. The method of claim 12,wherein the carboxylic acid ester comprises ethyl acetate.
 15. Themethod of claim 12, wherein the microorganism comprises a homoacetogenor a heteroacetogen.
 16. A method of making an alcohol, a carboxylicacid, a salt of a carboxylic acid, an ester of a carboxylic acid, or amixture of any of these, the method comprising: treating acarbon-containing material with one or more of radiation, sonication,pyrolysis, oxidation and steam explosion; converting at least a portionof the treated carbon-containing material utilizing a microorganism toproduce a product comprising one or more of an alcohol, a carboxylicacid, a salt of a carboxylic acid, a carboxylic acid ester or a mixtureof any of these; and capturing any carbon dioxide generated and/or anylignin liberated.
 17. The method of claim 16, wherein carbon dioxide iscaptured and the method further comprises sequestering the capturedcarbon dioxide.
 18. The method of claim 17, wherein sequestering carbondioxide comprises injecting captured carbon dioxide into a geologicalformation capable of maintaining carbon dioxide in place.
 19. The methodof claim 17, wherein sequestering carbon dioxide comprises fixing carbondioxide utilizing a microorganism.
 20. The method of claim 19, whereinthe microorganism fixes the carbon dioxide in the form of a carbohydrateand/or a lipid.
 21. The method of claim 19, wherein the microorganismfixes the carbon dioxide in the form of a lipid, the method furthercomprises converting the lipid to an ester.